Primary work toward #75 - introduces dashboard below Version's page. This is not a complete snapshot.
Merge branch 'master' of https://github.com/dipanm/redmine_release_notes

Conflicts:
	lib/redmine_release_notes/issue_patch.rb
First check-in for issue #75.

1. The release note generation can now be triggered from under the Version's own page.
2. Instead of the original _overview page, the whole new _dashboard page which is very elaborate
3. The dashboard not only shows the number of issues where release notes are generated/pending but also list the actual list of issue hence makes it easy to take appropriate action right immediately rather than hunting.
4. The original Release note tab exists as it is.
Release note generation and dashoard is tested for most scenarios

More discussion is required in finalizing the funcitonality